Error: Can't find common super class of

Question

I am trying to process with Proguard a MS Windows desktop application (Java 6 SE using the SWT lib provided by Eclipse). And I get the following critical error:

Answer 1

Try adding the option -dontskipnonpubliclibraryclasses to your command line.

From the Proguard Manual:

Limitations

For efficiency, ProGuard always ignores any private or package visible library classes while reading library jars. If any of them are extended by public library classes, and then extended again by input classes, ProGuard will complain it can't find them. In that case, you'll have to use the -dontskipnonpubliclibraryclasses option, and maybe even the -dontskipnonpubliclibraryclassmembers option. The graphical user interface has checkboxes for these settings.